The video embeded and linked below is a very simple and quick overview of creating a simple 3D digital twin using ArcGIS CityEngine without needing to source any of your own data!
https://youtu.be/-1Tb_0icvUg
All this comes from Esri's own datasets and OpenStreetMap!
If you want to see something specific let us know in the comments! Please like and subscribe to encourage us to do more content here. If you're looking for more, head over to our GD3D YouTube channel 🙂